Computer monitors are usually provided with a swivel base to allow the monitor screen to be oriented toward any desired direction. One of the monitor swivel bases that is available in the market comprises a three-piece construction. Such a three-piece swivel base, although working well, has a disadvantage of being too complicated to be manufactured in a labor- and cost-effective manner. Further, the three-piece structure requires at least three pieces of parts. This increases the warehousing cost.
Thus, a two-piece swivel base or rotatable bracket was developed, such as U.S. Pat. No. 5,465,936 and Taiwan patent publication No. 234595 which corresponds to the '936 U.S. patent of which an exploded perspective view is shown in FIG. 4 of the attached drawings. The rotatable bracket comprises a base plate 10 and a top plate 20 to be rotatably engaged on the base plate 10. A hemispherical recess 11 is formed on the base plate 10 with two grooves 13 defined thereon. A boss 14 extends upward from a center point of the recess 11 with a plurality of wings radially extending from the boss 14 at a distance from the recess 11. A post 15 further extends upward from the boss 14. An annular wall 12 provided on the base plate 10 surrounds the recess 11.
The top plate 20 comprises a concave section 24 corresponding to the recess 11 and having an elongated hole 22 and a square hole 23 in communication with each other formed thereon for fitting onto the distance between the wings and the surface of the recess 11 and thus mounting the top plate 20 on the base plate 10. A hook 21 with flat head 211 that defines a semi-circular cutout 212 is provided to shield the square hole 23 for positioning and retaining purpose. L-shaped ears 25 are provided on the top plate 20 for engaging a computer monitor (not shown).
This conventional two-piece swivel base structure has several disadvantages, such as:
(1) In positioning the top plate 20 relative to the base plate 10, the semi-circular cutout 212 is brought to contact the post 15 and if an un-expected great force is applied thereto, the hook 21 on which the cutout 212 is formed may be damaged.
(2) The configuration of the hook 21 that has the cutout 212 is difficult to molded.
(3) In dismounting the top plate 20 from the base plate 10, the flat head 211 has to be manually deformed and the design of the conventional structure may cause damage to the user's fingers and the hook 21.
Thus, it is desirable to have a two-piece swivel base structure which is simple in structure so as to overcome the drawback associated with the three-piece structure and which also overcomes the disadvantages of the prior art two-piece structure.